Order,disorder, and geometrical information indices of molecules

Structural features of various molecular systems with symmetry of point groups ranging fromC ₁ to the icosahedral symmetry are analyzed in the framework of the model suggested previously for the evaluation of order and disorder in the arrangement of atoms in a molecule based on the equationQ = I -P/3n (whereQ is the index of order, andP is the number of independent coordinates needed to fix ann-atomic molecule in the Cartesian coordinate system). TheQ value depends on various structural parameters of the molecule: the number of atoms in it, the symmetry, the dimensionality, and the number of structural degrees of freedom. The disorder indexP/3n = 1 -Q correlates with Shannon's entropy of information, andQ correlates with negentropy or excess information; this makes it possible to useP/3n as a new geometrical information molecular index that is obtained by a nonprobabilistic method. Analysis of the relationship between order and chaos in molecular systems, as well as of the specific order indexq =Q/n, makes it possible to identify both general and specific features of molecules.Translated from Izvestiya Akadernii Nauk. Seriya Khimicheskaya, No. 8, pp. 191219-121927, August, 1996.     

稀土在中国高新材料研制开发中的应用

我国在稀土资源和稀土原料的生产方面都居世界领先地位，近年来稀土高新材料的研制与开发也取得重大进展。本文概述了我国在稀土高新材料开发与研究方面的成果，指出今后应把稀土应用基础研究、中重稀土的应用研究和稀土在能源领域的应用研究作为重点进一步开展工作。     

Mechanism of thermal decomposition of cobalt acetate tetrahydrate

The thermal decomposition of cobalt acetate tetrahydrate (Co(CH₃COO)₂ · 4H₂O) has been studied via thermogravimetric (TG) analysis, in situ X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results of TG and XRD showed that the parent salt melted and then the dissolved crystalline water was vaporized in two steps. The dehydration process was followed by a major step concerning the decomposition of the acetate group, leading to basic acetate as an intermediate, which then produced CoO and Co in N₂ and H₂ atmosphere, respectively. Three decomposition intermediates Co(CH₃COO)₂ · 0.5H₂O, Co(CH₃COO)₂, and Co(OH)(CH₃COO) were presumed. In situ XRD experiments revealed that the intermediate basic acetate was poorly crystallized or even amorphous. Evolved gases analysis indicated that the volatile products of acetate decomposition were water vapor, acetic acid, ethylenone, acetone, and CO₂. A detailed thermal decomposition mechanism of Co(CH₃COO)₂ · 4H₂O was discussed.     

PREPARATION OF POLYMER MICROSPHERES WITH PYRIDYL GROUP AND THEIR STABILIZED GOLD METALLIC COLLOIDS

Narrow disperse poly(ethyleneglycol dimethacrylate-co-4-vinylpyridine)(poly(EGDMA-co-4-VPy))microspheres were prepared by distillation-precipitation copolymerization of ethyleneglycol dimethacrylate(EGDMA)and 4-vinylpyridine (4-VPy)with 2,2'-azobisisobutyronitrile(AIBN)as initiator in neat acetonitrile.The polymer microspheres containing pyridyl group were then utilized as stabilizer for gold metallic colloids with the diameter around 7 nm,which were prepared by the in situ reduction of gold chloride trihydrate with sodium borohydride through the coordination of the pyridyl group on the gel layer and surface of the microsphere with the gold metallic nano-particles.The catalytic properties of the pyridyl- functionalized microsphere-stabilized gold metallic colloids and the behavior of the stabilized-catalyst for the recycling were investigated with reduction of 4-nitrophenol to 4-aminophenol as a model reaction.     

纳米锐钛矿相变的原位XRD研究

钛氧化物具有3种物相：锐钛矿、板钛矿和金红石，其中，锐钛矿和板钛矿为室温稳定相．在温度较高的条件下会向热力学更稳定的金红石相转变。锐钛矿向金红石的相变是热力学亚稳定相向稳定相的转变，由于这种相变过程不存在平衡温度．分析研究其相变过程无论从理论方面还是从实际应用方面均具有重要的意义。     

微粉型四钼酸铵热容的测定

Single phase of ammonium tetramolybdate in the micro power form was prepared from polyphase ammonium paramolybdate. Its heat capacity from 14.25℃ to 120.12 ℃ was measured by drop method and the result is
Cp=0.3936+7.4047×10-4T+6.3543×10-3T-2(J•K-1•g-1)     

铂单晶电极表面不可逆反应动力学I.Pt(100)单晶电极上甲酸氧化的现场红外反射光谱研究

运用电化学暂态方法和现场时间分辨ＦＴＩＲ反射光谱研究甲酸在Ｐｔ（１００）单晶电极上的解离吸附和氧化过程,深入认识了甲酸解离吸附的反应速率在－０．２５至０．２５Ｖ电位区间呈火山形变化的规律。根据电化学现场时间分辨红外光谱的研究结果,提出在研究反动力学时避免甲酸解离吸附干扰的方法,为进一步研究甲酸在Ｐｔ（１００）电极表面经活性中间体直接氧化至ＣＯ２的反应动力学奠定了基础。     

硫醇和硫醚的沸点与分子结构之间关系的拓扑化学研究

根据分子拓扑学原理, 用染色因子标识原子性质的差异, 发展了一种适用于含原子分子体系结构性能关系研究的新方法。据此探讨了硫醇和硫醚的沸点与分子结构之间的关系, 提出一个既能合理表征结构性能关系, 又能预测沸点的定量关系式。     

In situ scanning FTIR microscopy and IR imaging of Pt electrode surface towards CO adsorption

In situ scanning FTIR microscopy was built up for the first time in the present work, which consists of an FTIR apparatus, an IR microscope, an X-Y mapping stage, and the specially designed electrochemical IR cell and computer software. It has been demonstrated that this new space-resolvd in situ IR technique can be used to study vibration properties of micro-area, and to perform IR imaging of electrode surface. The chemical image obtained using this technique fur CO adsorption on Pt electrode illustrated, at a space-resolution of 10~(-2) cm, the inhomogeneity and the distribution of reactivity of micro-area of electrode surface.     

土壤淋溶柱色谱中同系物、氯代苯保留值与流动相组成、沸点的交点规律

基于土壤淋溶柱色谱符合logk'-ψ的线性保留方程,在同系物（正构烷基苯、甲基苯）和氯代苯中,同类溶质与固定相（土壤）和淋洗剂（甲醇-水）有相似的作用方式,所以溶质保留值（logk'）与淋洗剂有机调节剂浓度间存在浓度交点,与沸点间存在沸点交点规律,并用实验进行了验证。